Bill Gates was born in 1955 and grew up in Seattle, Washington. As a child, he attended the Lakeside School, a private prep school. There, he joined the computer club, which taught programming and paid for access to a mainframe computer for students to practice on. What he learned in the club enabled him to get part-time work at two small computer companies. Then he and a friend learned that the mainframe at the University of Washington sat idle between three and six o’ clock in the morning even though the computer center was open. The campus was close enough to walk to, and they snuck out of their houses at night to go use that mainframe. He became obsessed with computers.

Gates attended Harvard University for two years before dropping out to start the computer company Microsoft with childhood friend Paul Allen in 1975. Allen left the company in 1983, and Gates ran it until 2000, when Steve Ballmer became CEO. Gates continued to work on software until 2008, when he began devoting all his time to philanthropic work through the Bill & Melinda Gates Foundation, which he and his former wife founded in 2000. The foundation focused on health care, education, and development worldwide.